The SZ-Z4 is a CR-type coil surge suppression unit designed for use with Fuji Electric magnetic contactors and starters in the SC and SW series. It employs a Capacitor-Resistor (CR) circuit connected in parallel with the contactor coil to suppress abrupt increases in surge voltage by lowering the surge voltage oscillation frequency. The unit is rated for 24-48V AC/DC coil voltage and can be easily connected to contactor coil terminals without requiring additional installation space. This surge suppression unit protects adjacent electronic devices such as programmable logic controllers from damage or malfunction caused by coil induction transients during ON-OFF operations. The CR type design is effective in both AC and DC circuits, making it suitable for diverse industrial control applications.